1. Field of the Invention
This invention relates to methods for preparation of basic hydrogen peroxide (BHP) including the generation and regeneration thereof in a chemical system that saves weight and lessens environmental impact.
2. The Prior Art
Basic hydrogen peroxide (BHP), is the principle fuel for Chemical Oxygen-Iodine Lasers (COIL). A COIL laser is a chemically pumped gas dynamic electronic transition laser. COIL systems show marked potential for both military and industrial application due to inherent system benefits. Chemical laser devices have a much greater degree of scalability to higher power regions than photolytic and solid state devices which can be adversely affected by the increased thermal loading. Chemical lasers have higher efficiencies (20-30%), particularly at applicable and useful power levels. The COIL wavelength at 1.315 .mu.m is also ideally suited for industrial applications. It has outstanding fiber optic transmission qualities, and it couples well with metals allowing for the use of lower power devices without sacrificing welding/cutting effectiveness. The final, and possibly most important benefit of COIL is the excellent beam quality. Gas dynamic lasers are known to have very good beam quality, but COIL is even unique among this class of devices. COIL operates on an electronic transition producing an inherently higher quality beam, as opposed to a vibrational (CO/CO.sub.2) or rotational transition (HF/DF) lasers. This significantly higher beam quality gives cleaner cuts and welds, along with simpler beam splitting and direction.
The chemical pump for COIL systems is the electronically excited, singlet delta state of molecular oxygen (O.sub.2.sup.1 .DELTA.). A chemical reaction between chlorine and Basic Hydrogen Peroxide produces the O.sub.2.sup.1 .DELTA.. This metastable state of excited oxygen then collisionally transfers its energy to iodine, the actual lasing species of COIL.
The fundamental source of O.sup.2.sup.1 .DELTA. and hence the output laser power is the BHP fuel and its reactive species. This unique and rather unstable solution of aqueous, alkaline hydrogen peroxide is generated in the prior art, by reacting aqueous metal hydroxides (usually potassium hydroxide) with an excess of hydrogen peroxide. The primary reactive species in BHP is the hydroperoxide ion, O.sub.2 H.sup.-, which is normally generated according to the following equation: EQU OH.sup.- +H.sub.2 O.sub.2 +K.sup.+ .fwdarw.O.sub.2 H.sup.- +H.sub.2 O+K.sup.+ ( 1)
The BHP reacts with chlorine gas in the singlet oxygen generator to evolve the excited oxygen as follows: EQU Cl.sub.2 +20.sub.2 H.sup.- +2K.sup.+ .fwdarw.H.sub.2 O.sub.2 +2KCl+O.sub.2.sup.1 .DELTA. (2)
BHP is said to be depleted, and hence disposed of when the hydroperoxide ion concentration falls below levels sufficient to maintain lasing. Currently, this means that only 10 weight percent of the fuel is utilized by the device, and the rest is wasted in addition to requiring an environmentally critical neutralization prior to disposal.
That is, considerable chemical waste streams are produced by the above prior art procedure of reaction (2). Also additional reactants must be employed and reaction (2) repeated, so that reactants and previously spent reactants add considerable weight to the COIL system. Also there are the considerable hazards of Hydrogen Peroxide transportation and handling to replace the above quickly depleted BHP fuel.
An example of the above prior art procedure is given in U.S. Pat. No. 5,229,100 to G. M. Harpole (1993).
Accordingly there is need and market for an improved BHP generation process that significantly overcomes the above prior art shortcomings.
There has now been discovered an improved method for preparation of BHP with marketly reduced waste of reactants and that significantly decrease COIL system weights and environmental impacts.